Biopsy forceps for endoscopic usage characteristically include a pair of pivotally mounted jaws mounted at the distal end of a tubular support member. Rigid instrument constructions utilize a rigid tube for supporting the jaws. Flexible constructions utilize a flexible tubular cable for supporting the jaws.
Rigid instruments of this type tend to be more expensive, and are intended to be re-used. They are designed for this, and are rather easily cleaned and sterilized for their next use.
However, flexible instruments involve a different set of problems, one of which is the near impossibility of cleaning such instruments, especially when the jaw mount is permanently attached to the support cable. The internal dimensions and clearances are very small, and because the cables are tightly wound helical springs, it is impractical to reach the inside of the support cable to clean it. As a consequence, flexible biopsy forceps are usually discarded after a single use. The mount, the jaws, and the control wire are the greatest part of the cost of the instrument. The support cable is not very expensive, but the jaws are quite expensive because they are small, held to close tolerances, and have sharpened cutting edges.
Accordingly, if an arrangement can be made such that the jaw mount can readily be removed and replaced, then it along with the jaws and control wire which are attached to it can easily be cleaned. Then the inexpensive support cable can be discarded and replaced with a new clean one. The expensive parts of the instrument are thereby saved and re-used. The only cost for re-use is the small expense of a new support cable.
As simple as this objective sounds, it has not heretofore been attained because of the difficulty of removably attaching the mount to the resilient spring-wound support cable. The spring cannot be threaded, and it is impractical to form internal threads in the small jaw mount. Accordingly, the jaw mounts have been permanently affixed, such as by crimping, which prevents the mount from being removed and re-used. Such an instrument is not re-usable because it cannot be cleaned.
It is an object of this invention to take advantage of an inherent property of the support cable to enable a jaw mount to be removably mounted to a helically-formed support cable, and then be applied readily to another one.